Tuesday, January 21, 2020

JEE Main Chemistry Revision - Concepts and Definitions


Read Every Day 10 Points and Think of the other points that are implied by them. 

This process will help you to complete intensive study of all the concepts  of the subject by the time you appear for JEE Main in April 2020.


12 January 2019

Haloalkanes and Haloarenes

JEE Syllabus

UNIT 22: ORGANIC COMPOUNDS CONTAINING HALOGENS

General methods of preparationproperties and reactions; Nature of C-X bond; Mechanisms of substitution reactions. Uses; Environmental effects of chloroform - iodoform.

1. The groups which possess two nucleophilic centres are called ambident nucleophiles.

Explanation: An ambident nucleophile has "teeth" on two sides.

It can attack from two different places and form two different products.

For example, the thiocyanate ion, SCN⁻, is a ambident nucleophile. It is a resonance hybrid.

Both the S  and the N  atoms can act as nucleophiles.

So, the SN2  reaction of an alkyl halide with SCN⁻  often leads to a mixture of an alkyl thiocyanate and an alkyl isothiocyanate.

R-X+SCN⁻→X⁻   + R-SCN          + R-NCS
                alkyl            alkyl
                thiocyanate      isothiocyanate
https://socratic.org/questions/what-is-an-ambident-nucleophile


2. The rate of reaction depends on the concentration of both alkyl halid and base, the reation is known as SN2 reactions.

3. The rate of reaction depends on the concentration of alkyl halides, the reaction is known as SN1 reaction.

4. The order of reactivity of alkyl halides for SN1 reactions

3 degree halide > 2 degree halide > 1 degree halide > CH3X
(tertiary)              (secondary)           (primary)

5. The order of reactivity of alkyl halides for SN2 reactions

3 degree halide < 2 degree halide < 1 degree halide < CH3X

6.  In SN1 and SN2 mechanism, the reactivity of halides follows the order

R-I > R-Br > R-Cl > R-F

7. If all the substituents attached to a carbon are different, that carbon is called asymmetric (or) Chiral carbon or stereocentre.

8. The stereo isomers related to each other as non-super imposable images are called enantiomers.

9. A mixture containing two enantiomers in equal proportions will have zero optical rotation, as the rotation due to one isomer will be exactly cancelled by the rotation due to the other isomer. Such a mixture is known as racemic mixture or racemic modification.

10. The process of conversion of enantiomer into a racemic mixture is known as racemisation.


Key words:  ambident nucleophiles, SN2 reactions, SN1 reaction, The order of reactivity of alkyl halides for SN1 reactions (degree of halides),  The order of reactivity of alkyl halides for SN2 reactions(degree of halides), order of  reactivity of halides (based on halogen), asymmetric (or) Chiral carbon or stereocentre, enantiomers, racemic mixture or racemic modification, racemisation.

13 January 2020

11. SN2 reactions of optically active halides are accompanied by inversion of configuration.

12. SN1 reactions are accompanied by racemisation.

13. Finkelstein reaction - The reaction of alkyl chloride (or) bromide with NaI in dry acetone gives Alkyl iodides.

14. Swarts reaction -The reaction of alkyl chloride (or) bromide with metal flourides like AgF, Hg2F2, CoF2, SbF3 on heating gives alkyl fluorides.

15. Haloalkane reacts with KCN to form alkyl cyandie as main product where haloalkane reacts with AgCN to form alkyl isocyanide as the main product.

16. Sandmeyer's reaction - The reaction of benzene diazonium salt with cuprous chloride (or) bromide and HCl gives chlorobenzene or bromobenzene.

Reactions of Cholorobenzene

17. Cholorobenzene reacts with chlorine in presence of AlCl2 gives 1,4-dichlorobenzene as a major product, and 1,2 -dichlorobenzene as a minor product.

18. Cholorobenzene reacts with nitration mixture and gives 1-chloro-4-nitrobenzene as a major product and 1-chloro-2-nitrobenzene as a minor product.

19. Cholorobenzene reacts with CH3Cl in presence of AlCl3 adn gives 1-chloro-4-methylbenzene as a major product and 1-chloro-2-methyl benzene as a minor product.

20. Cholorobenzene reacts with CH3COCl in presence of AlCl3 and gives 4-chloro-acetophenone as a major product and 2-chloro-acetophenone as a minor product.

14 January 2020

21. Fittig reaction: Cholorobenzene reacts with sodium in presence of dry ether - gives diphenyl.

22. Wurtz-Fittig reaction: Cholorobenzene, alkyl halide and sodium react in presence of dry ether and give alkyl benzene.

23. DDT = P, p1-dichlorodiphenyltrichloroethane

24. Grignard reagent (RMgX): Obtained by the reaction of haloalkanes with magnesium metal in dry ether.

25. Freons (CCl2F2) are chlorofluoro compounds of methane and ethane.

26. In dehydrohalogenation reactions, the preferred product is that alkene which has the greater number of alkyl groups attached to the doubly bonded carbon atoms.

Organic Compounds with Functional Groups OH and CHO

JEE Syllabus

UNIT 23: ORGANIC COMPOUNDS CONTAINING OXYGEN

General methods of preparation, properties, reactions and uses

ALCOHOLS, PHENOLS AND ETHERS

Alcohols: Identification of primary, secondary and tertiary alcoholsmechanism of dehydration.

Phenols: Acidic nature, electrophilic substitution reactions: halogenation, nitration and sulphonationReimer – Tiemann reaction.

Ethers: Structure.

Aldehyde and Ketones: Nature of carbonyl group;Nucleophilic addition to >C=O group, relative reactivities of aldehydes and ketones; Important reactions such as – Nucleophilic addition reactions (addition of HCN, NH3 and its derivatives), Grignard reagent; oxidationreduction (Wolff Kishner and Clemmensen); acidity of α – hydrogen, aldol condensationCannizzaro reactionHaloform reaction; Chemical tests to distinguish between aldehydes and Ketones.

Carboxylic acidsAcidic strength and factors affecting it.

Alcohols and Phenols

1. Methanol (CH3OH) is referred to as wood spirit.

Alcohol from alkenes

2. Alkenes react with water in the presence of acid as catalyst to form alcohols.

Mechanism of alcohol formation

3. Protonation of alkene to form carbocation by electrophylic attack of H3O+.

4. Nucleophylic attack of water on carbocation.

5. Deprotonation to form an alcohol

Key words:   Fittig reaction, Wurtz-Fittig, DDT,  Grignard reagent , Freons,  preferred product in dehydrohalogenation reactions of halides, wood spirit., Alcohol from alkenes ,


15 January 2020

6. Diborane (BH3)2 reacts with alkenesto give trialkyl boranes as addition product.

7. Trialkyl borane is oxidized to  alcohol by hydrogen peroxide in the presence of acqueous sodium hydroxide.

8. With sodium borohydride (NaBh4) or lithiumaluminium hydride (LiAlH4), aldehydes yield primary alcohols. Ketones give secondary alcohols.

9. Primary (1 degree), secondary (2 degree) and tertiary (3 degree) alcohols are distinguished by Lucas test.

Preparation of Phenol

10. Chlorobenzene is fused with NaOH at 623K and 320 atmospheric pressure.  ... Phenol is obtained by acidification of sodium phenoxide.

11. Benzene is sulphonated with oleum and benzene sulphonic is acid formed. The acid is converted to sodium phenoxide on heating with molten sodium hydroxide. Phenol is obtained by acidification of sodium phenoxide.

High boiling points of alcohols

12. The high boiling points of alcohols are mainly due to the presence of intermolecular hydrogen bonding in them which is not present in ethers and hydrocarbons.

13. Propanol has higher boiling point than that of hydrocarbon n-butane due to intermolecular hydrogen bond.

Solubility of alcohols and phenols

14. Solubility of alcohols and phenols in water is due to their ability to form hydrogen bonds with water molecules.

15. The solubility decreases with increase in size of alkyl/aryl groups. Several lower molecular mass alcohols are misible with water in all proportions.

16 January 2020

Acidic nature of phenol.


16. The reactions of phenol with metals (sodium, alumimium) and sodium hydroxide indicate its acidic nature.

For details read: Acidic nature of phenols

17. The hydroxyl group, in phenol is directly attached to the sp2 hybridized carbon of benezene ring which acts as an electron withdrawing group.

18. The reaction of phenol with acqueous sodium hydroxide indicates that phenols are stronger acids than alcohols and water.

19. Due to the higher electronegativity of sp2 hybridised carbon of phenol to which -OH is attached electron density decreases on oxygen.

20. The presence of electron withdrawing groups such as nitro group, enhances the acidic strength of phenol.

21. The effect is more pronounced when withdrawing group is present at ortho and para positions. It is due to the effective delocalisation of negative charge in phenoxide ion.

Oxidizing alcohols 

22. Strong oxidizing agents such as potassium permanganate are used for getting carboxylic acids from alcohols directly.

23. CrO3 in anhydrous medium is used as the oxidizing agent for the isolation of aldehydes.

24. A better reagent for oxidation of primary alcohols to aldehydes in good yield is pyridium chlorochromate (PCC), a complex of chromium trioxide with pyridine and HCl.

25. The -OH group attached to the benzene ring activates it towards electrophilic sustituion. Also it directs the incoming group to ortho and para positions in the ring as these positions become electron rich due to the resonance effect caused by -OH group.


17 January 2020


26. The ortho and para isomers can be separated by steam distillation.

27. Kolbe's reaction: Phenol is treated with sodium hydroxide and carbon dioxide to from salicylic acid.

28. Reimer - Tiemann reaction:Phenol reacts with chloroform in the presence of sodium hydroxide to form salicylaldehyde.

29. Reduction of phenol with zinc dust forms benzene.

30. Oxidation of phenol with chromic acid produces a conjugated diketone known as benzoquinone.

31. Williamson synthesis:

32. Anisole reacts with the alkylhalide and acyl halide in the presence of anhydrous aluminium chloride as catalyst. The alkyl and acyl groups are introduced at ortho and para positions in the resultant  products.

33. Nitration: Anisole reacts with a mixture of concentrated sulphur amd nitric acid to yield a mixture of ortho and para nitroanisole.


18 January 2020

Aldehydes, Ketones and Carboxylic Acids

1. Friedel-craft acylation: Benzene is treated with acetylchloride in the presence of AlCl3 to form acetophenone.

2. Cannizaro reaction: Aldehydes which do not have α-hydrogen atom react with concentrated sodium hydroxide (NaOH) or potassium hydroxide (KOH) in such a way that one molecule get oxidized to acid and the second molecule gets reduced to alcohol.

Note two molecules of aldehyde participates in the reaction.

This self oxidation-reduction under the influence of a base is known as the Cannizzaro's reaction.

Formaldehyde does not possess α-hydrogen atom and therefore undergoes Cannizzaro's reaction. Acetaldehyde does not give this reaction.

3. Aldol Condensation: Aldehydes and ketones containing α-hydrogen (H-atoms attached to the C-atom adjacent to the carbonyl group)undergo condensation in the presence of dilute alkali.

In the resulting compound both aldehyde group and alcohol group are present.

acetaldehyde and acetone undergo aldol condensation.
Formaldehyde, banzaldehyde do not undergo aldol condensation.

4. Cross aldol condensation: Aldol condensation  carried out between different aldehydes (or) ketones. In this process 4 products are obtained.

5. Acid salts are heated with sodalime loose CO2 to form hydrocarbons.

6. HVZ reaction:

7. Carbonyl compounds participate in nucleophylic addition reactions.

8. Carbonyl compounds are treated with HCN to form Cynohydrins.

9. Aldehydes react with one molecule of alcohol in the presence of dry HCL and form alkoxy alcohols. It is called hemiacetal.

10. Aldehydes react with two  molecules of alcohol and form dialkoxy compounds.  It is called acetal.


19 January 2020

11. Formation of semicarbozone:

12. Formation of oxime:

JEE Syllabus topic: Carboxylic acids: Acidic strength and factors affecting it.

13. Presence of electron withdrawing groups increases acidic nature of Carboxylic Acids.

14. Presence of electron releasing groups decreases acidic nature of Carboxylic Acids

15. Feling's reagent.

16. Fehling test

17. Tollen's reagent

18. Tollen's test

19. In benzoic acid electrophylic substitution takes place at meta position.

20. Acetic acid is treated with PCl3/PCl5 to form Benzamide.

20 January 2020

21. Formation of Benzamide

22. Increasing order of acidic strength of various benzoic acids.

23. Decreasing order of acidic strength of given carboxilic acids

Organic Compounds Containing Nitrogen - Amines


JEE Syllabus

UNIT 24: ORGANIC COMPOUNDS CONTAINING NITROGEN

General methods of preparation, properties, reactions and uses

Amines: Nomenclatureclassification, structure, basic character and identification of primary, secondary and tertiary amines and their basic character.

Diazonium Salts: Importance in synthetic organic chemistry.


1. What are amines?

2, Preparation of aniline.

3. Ammonolysis

4. Reactity of halides with amines - order

5. Primary amines from nitriles

6. Primary amines from amides

7. Gabriel phthalimid synthesis

21 January 2020

8. Hoffman bromamide degradation reaction.

9. Boiling points of different amines.

10. Order of basic nature of amine (Remember acidic nature of phenols)

11. Amines behave as Lewis bases.

12. Alkylation of amines.

13. Acetylation of amines.

14. Benzoylation of amines

15. Carbylamine reaction

16. Amines - nitrous acid reation

17. Diazotisation


22 January 2020

18. Hinsberg reagent

19. Formation of sulphonamide

20. reaction of tertiary amines

21. Ortho and para directing and ring activating group

22. 2,4,6,  tri bromo aniline formation

23. Nitration reaction of aniline

24. Zwitterion

25. Aniline and Friedal crafts reaction

26. Benzene diazonium chloride.

27. Diazonium salt general formula

23 January 2020

28.Sandmeyer reaction

29. Gatterman reaction

Cyanides

1. Formation of cyanides - Aldoximes are dehydrated by acetic anhydride.

2. Hydrolysis of isocyanides

3. Cyanides reaction with Grignard reagent.

4. Cyanides reaction with LiAlH4

5. Ioscyanides reduction with H2/Ni

6. Oxidation of isocynaides


24 January 2020

Inorganic Chemistry

General Principles of Metallurgy

1. Mineral

2. Ore

3. Flux

4. Gangue

5. Slag

6. Matte

7.  Concentration of Ore

8. Froth flotation process


10. Roasting: Process of heating in presence of air.


25 January 2020

11. Calcination

12. Electrometallury

13. Blast furnace - Chemical reactions

14. Extraction of coppoer from copper pyrites

15. Electrolytic refining of copper

16. Ore of aluminium

17. Electrolytic reduction of pure alumina.

18. General methods of refining

19. Role of cryolite

20. Fractional crystallization

26 January 2020

21. Vapour phase refining

22. Composition of alloys. - Brass

23. Uses of metal zinc

24. Uses of metal copper

25. Uses of metal iron

26. Uses of metal aluminium

27. Uses of cast iron

28. Uses of wrought iron

29. Uses of nickel steel

30. Uses of stainless

27 January 2020

P-Block Elements




Updated 20 January 2020,  17 January 2020,




Saturday, January 18, 2020

Carboxylic acids: Acidic strength and factors affecting it



A. Reactions due to hydrogen atom of carboxyl group

1. Acidic character

a. Action with blue litmus
all carboxylic acids turn blue litmus red.


b. Reaction with metals: liberation of hydrogen
Carboxylic acids react with active metals such as Na, K, Ca, Mg, Zn, etc., to form their salts with the liberation of hydrogen.

c. Action with alkalies: formation of salts
Carboxylic acids neutralize alkalies forming salts and water.

d. Action with carbonates and bicarbonates: evolving carbon dioxide
Carboxylic acids decompose carbonates and bicarbonates evolving carbon dioxide with brisk effervescence.


Mechanism of acidic character



In the COOH group due to resonance in the OH, O acquires some positive charge the electron pair of OH is drawn towards O. This displacement of electrons causes the release of a proton and a carboxylate ion, RCOO- is formed. This is the reason for acidic character of carboxylic acids.

The strength of acids can be expressed in terms of dissociation constant Ka or Ph number of PKa number which is pKa = -log Ka

A stronger acid will have a higher Ka value but smaller PKa value.

Effects of substituents on acidic strength of acids

Electron releasing substituents: Alkyl is an electron releasing group. If the H atom of formic acid (HCOOH) is replaced by CH3 group to form acetic acid (CH3COOH) the alkyl group will tend to increase the electron density on the oxygen atom of the O-H bond. This increase will make removal H+ ion difficult in comparison to formic acid.

Acetic acid is a weaker acid in comparison to formic acid.

The electron release effect is called +I effect. As +I effect increases, acidic strength will go down. As more alkyl groups are there +I effect increases
CH3
Therefore acidic property is stronger or more for CH3COOH.

Acidic strength is in the following order
acidic strength of HCOOH>CH3COOH>CH3CH2COOH>(CH3)2CHCOOH

Electron withdrawing substituents: Substituents like halogens tend to withdraw the electron charge. Halogens are electron attracting atoms(-I inductive effect). They withdraw the electrons from the carbon to which they are attached and this effect is transmitted throught the chain. The increases positive charge on O atom in the O-H bond and dissociation of H+ ion or proton takes place more easily.

Hence chloroacetic acid is stronger acid than acetic acid.


Friday, January 17, 2020

Blog-directories

IIT JEE Revision - Ch.28 Carboxylic Acid - Core Points

JEE syllabus

Carboxylic acids:
Preparation, properties
Characteristic reactions
formation of esters,
acid chlorides and amides,
ester hydrolysis;


---------
1. Carboxylic acids are the compound containing carboxyl group in their molecules.

-C with a double bond with oxygen and single bond with OH

2. These acids can be aliphatic or aromatic.

aliphatic acids:

Formic acid HCOOH
Acetic acid CH-3COOH
Isobutyric acid (Branched)

aromatic acids

Bezoic acid : H in benzene substituted by COOH

m-Nitrobenzoic acid: One more H substituted by NO-2

o-Toluic acid (o refers to ortho) Benzoic acid with one more H substituted by CH-3

3. Methods of Preparation of Monocarboxylic Acids:
1. From oxidation of primary alcohols
2. By oxidation of aldehydes and ketones.


A. Reactions due to hydrogen atom of carboxyl group

1. Acidic character

a. Action with blue litmus
all carboxylic acids turn blue litmus red.


b. Reaction with metals: liberation of hydrogen
Carboxylic acids react with active metals such as Na, K, Ca, Mg, Zn, etc., to form their salts with the liberation of hydrogen.

c. Action with alkalies: formation of salts
Carboxylic acids neutralize alkalies forming salts and water.

d. Action with carbonates and bicarbonates: evolving carbon dioxide
Carboxylic acids decompose carbonates and bicarbonates evolving carbon dioxide with brisk effervescence.


Mechanism of acidic character



In the COOH group due to resonance in the OH, O acquires some positive charge the electron pair of OH is drawn towards O. This displacement of electrons causes the release of a proton and a carboxylate ion, RCOO- is formed. This is the reason for acidic character of carboxylic acids.

The strength of acids can be expressed in terms of dissociation constant Ka or Ph number of PKa number which is pKa = -log Ka

A stronger acid will have a higher Ka value but smaller PKa value.

Effects of substituents on acidic strength of acids

Electron releasing substituents: Alkyl is an electron releasing group. If the H atom of formic acid (HCOOH) is replaced by CH3 group to form acetic acid (CH3COOH) the alkyl group will tend to increase the electron density on the oxygen atom of the O-H bond. This increase will make removal H+ ion difficult in comparison to formic acid.

Acetic acid is a weaker acid in comparison to formic acid.

The electron release effect is called +I effect. As +I effect increases, acidic strength will go down. As more alkyl groups are there +I effect increases
CH3
Therefore acidic property is stronger or more for CH3COOH.

Acidic strength is in the following order
acidic strength of HCOOH>CH3COOH>CH3CH2COOH>(CH3)2CHCOOH

Electron withdrawing substituents: Substituents like halogens tend to withdraw the electron charge. Halogens are electron attracting atoms(-I inductive effect). They withdraw the electrons from the carbon to which they are attached and this effect is transmitted throught the chain. The increases positive charge on O atom in the O-H bond and dissociation of H+ ion or proton takes place more easily.

Hence chloroacetic acid is stronger acid than acetic acid.



Some more topics need to be covered


Carboxylic acid - practice questions
http://makoxmcqs.com/chemistry-mcqs-for-jee-main-carboxylic-acids-and-their-derivatives-mcq-practice-sheet/


Updated on 18 January 2020
5 February  2008


Tuesday, January 14, 2020

JEE Main Chemistry 2020 Syllabus - Revision Notes


 IIT JEE Main Chemistry syllabus

SECTION: A

PHYSICAL CHEMISTRY

UNIT 1: SOME BASIC CONCEPTS IN CHEMISTRY

Matter and its nature, Dalton’s atomic theory; Concept of atom, molecule, element and compound; Physical quantities and their measurements in Chemistry, precision and accuracy, significant figures, S.I. Units, dimensional analysis; Laws of chemical combination; Atomic and molecular masses, mole concept, molar mass, percentage composition, empirical and molecular formulae; Chemical equations and stoichiometry.

UNIT 2: STATES OF MATTER

Classification of matter into solid, liquid and gaseous states
Gaseous State: Measurable properties of gases; Gas laws – Boyle’s law, Charle’s law, Graham’s law of diffusion, Avogadro’s law, Dalton’s law of partial pressure; Concept of Absolute scale of temperature; Ideal gas equation; Kinetic theory of gases (only postulates); Concept of average, root mean square and most probable velocities; Real gases, deviation from Ideal behaviour, compressibility factor and van der Waals equation.
Liquid State: Properties of liquids – vapour pressure, viscosity and surface tension and effect of temperature on them (qualitative treatment only).
Solid State: Classification of solids: molecular, ionic, covalent and metallic solids, amorphous and crystalline solids (elementary idea); Bragg’s Law and its applications; Unit cell and lattices, packing in solids (fcc, bcc and hcp lattices), voids, calculations involving unit cell parameters, imperfection in solids; Electrical, magnetic and dielectric properties.

UNIT 3: ATOMIC STRUCTURE

Thomson and Rutherford atomic models and their limitations; Nature of electromagnetic radiation, photoelectric effect; Spectrum of hydrogen atom, Bohr model of hydrogen atom – its postulates, derivation of the relations for energy of the electron and radii of the different orbits, limitations of Bohr’s model; Dual nature of matter, de-Broglie’s relationship, Heisenberg uncertainty principle
Elementary ideas of quantum mechanics, a quantum mechanical model of the atom, its important features
Concept of atomic orbitals as one electron wave functions; Variation of Ψ and Ψ2 with r for 1s and 2s orbitals; various quantum numbers (principal, angular momentum and magnetic quantum numbers) and their significance; shapes of s, p and d – orbitals, electron spin and spin quantum number; Rules for filling electrons in orbitals – Aufbau principle, Pauli’s exclusion principle and Hund’s rule, electronic configuration of elements, extra stability of half-filled and completely filled orbitals.

UNIT 4: CHEMICAL BONDING AND MOLECULAR STRUCTURE

Kossel – Lewis approach to chemical bond formation, the concept of ionic and covalent bonds.
Ionic Bonding: Formation of ionic bonds, factors affecting the formation of ionic bonds; calculation of lattice enthalpy.
Covalent Bonding: Concept of electronegativity, Fajan’s rule, dipole moment; Valence Shell Electron Pair Repulsion (VSEPR) theory and shapes of simple molecules. Quantum mechanical approach to covalent bonding: Valence bond theory – Its important features, the concept of hybridisation involving s, p and d orbitals; Resonance.
Molecular Orbital Theory – Its important features, LCAOs, types of molecular orbitals (bonding, antibonding), sigma and pi-bonds, molecular orbital electronic configurations of homonuclear diatomic molecules, the concept of bond order, bond length and bond energy.
Elementary idea of metallic bonding. Hydrogen bonding and its applications.

UNIT 5: CHEMICAL THERMODYNAMICS

Fundamentals of thermodynamics: System and surroundings, extensive and intensive properties, state functions, types of processes.
First law of thermodynamics – Concept of work, heat internal energy and enthalpy, heat capacity, molar heat capacity; Hess’s law of constant heat summation; Enthalpies of bond dissociation, combustion, formation, atomization, sublimation, phase transition, hydration, ionisation and solution.
The second law of thermodynamics; Spontaneity of processes; ΔS of the universe and ΔG of the system as criteria for spontaneity, Δg° (Standard Gibbs energy change) and equilibrium constant

UNIT 6: SOLUTIONS

Different methods for expressing concentration of solution – molality, molarity, mole fraction, percentage (by volume and mass both), vapour pressure of solutions and Raoult’s Law – Ideal and non-ideal solutions, vapour pressure – composition, plots for ideal and non-ideal solutions; Colligative properties of dilute solutions – relative lowering of vapour pressure, depression of freezing point, elevation of boiling point and osmotic pressure; Determination of molecular mass using colligative properties; Abnormal value of molar mass, van’t Hoff factor and its significance.

UNIT 7: EQUILIBRIUM

https://iit-jee-chemistry.blogspot.com/2015/05/jee-main-core-points-for-revision.html

Meaning of equilibrium, the concept of dynamic equilibrium

Equilibria involving physical processes: Solid-liquid, liquid – gas and solid – gas equilibria, Henry’s law, general characteristics of equilibrium involving physical processes.

Equilibria involving chemical processes: Law of chemical equilibrium, equilibrium constants (Kp and Kc) and their significance, the significance of ΔG and ΔG° in chemical equilibria, factors affecting equilibrium concentration, pressure, temperature, the effect of catalyst; Le Chatelier’s principle.

Ionic equilibrium: Weak and strong electrolytes, ionization of electrolytes, various concepts of acids and bases (Arrhenius, Bronsted – Lowry and Lewis) and their ionization, acid-base equilibria (including multistage ionization) and ionization constants, ionization of water, pH scale, common ion effect, hydrolysis of salts and pH of their solutions, solubility of sparingly soluble salts and solubility products, buffer solutions.


UNIT 8: REDOX REACTIONS AND ELECTROCHEMISTRY

Electronic concepts of oxidation and reduction, redox reactions, oxidation number, rules for assigning oxidation number, balancing of redox reactions
Electrolytic and metallic conduction, conductance in electrolytic solutions, specific and molar conductivities and their variation with concentration: Kohlrausch’s law and its applications.
Electrochemical cells – Electrolytic and Galvanic cells, different types of electrodes, electrode potentials including standard electrode potential, half – cell and cell reactions, emf of a Galvanic cell and its measurement; Nernst equation and its applications; Relationship between cell potential and Gibbs’ energy change; Dry cell and lead accumulator; Fuel cells.


UNIT 9: CHEMICAL KINETICS

Rate of a chemical reaction, factors affecting the rate of reactions: concentration, temperature, pressure and catalyst; elementary and complex reactions, order and molecularity of reactions, rate law, rate constant and its units, differential and integral forms of zero and first order reactions, their characteristics and half-lives, effect of temperature on rate of reactions – Arrhenius theory, activation energy and its calculation, collision theory of bimolecular gaseous reactions (no derivation).

UNIT-10: SURFACE CHEMISTRY

Adsorption – Physisorption and chemisorption and their characteristics, factors affecting the adsorption of gases on solids – Freundlich and Langmuir adsorption isotherms, adsorption from solutions.

Colloidal state – distinction among true solutions, colloids and suspensions, classification of colloids – lyophilic, lyophobic; multi molecular, macromolecular and associated colloids (micelles), preparation and properties of colloids – Tyndall effect, Brownian movement, electrophoresis, dialysis, coagulation and flocculation; Emulsions and their characteristics.

Chemistry Syllabus for IIT JEE Main

SECTION – B

INORGANIC CHEMISTRY

UNIT 11: CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES

Modem periodic law and present form of the periodic table, s, p, d and f block elements, periodic trends in properties of elements atomic and ionic radii, ionisation enthalpy, electron gain enthalpy, valence, oxidation states and chemical reactivity.c

UNIT 12: GENERAL PRINCIPLES AND PROCESSES OF ISOLATION OF METALS

Modes of occurrence of elements in nature, minerals, ores; Steps involved in the extraction of metals – concentration, reduction (chemical and electrolytic methods) and refining with special reference to the extraction of Al, Cu, Zn and Fe; Thermodynamic and electrochemical principles involved in the extraction of metals.

UNIT 13: HYDROGEN

Position of hydrogen in periodic table, isotopes, preparation, properties and uses of hydrogen; Physical and chemical properties of water and heavy water; Structure, preparation, reactions and uses of hydrogen peroxide; Hydrogen as a fuel

UNIT 14: S – BLOCK ELEMENTS (ALKALI AND ALKALINE EARTH METALS)

Group – 1 and 2 Elements

General introduction, electronic configuration and general trends in physical and chemical properties of elements, anomalous properties of the first element of each group, diagonal relationships
Preparation and properties of some important compounds – sodium carbonate and sodium hydroxide; Industrial uses of lime, limestone, Plaster of Paris and cement; Biological significance of Na, K, Mg and Ca.


UNIT 15: P – BLOCK ELEMENTS

Group – 13 to Group 18 Elements

General Introduction: Electronic configuration and general trends in physical and chemical properties of elements across the periods and down the groups; unique behaviour of the first element in each group.

Group-wise study of the p – block elements

Group – 13: Preparation, properties and uses of boron and aluminium; properties of boric acid, diborane, boron trifluoride, aluminium chloride and alums.
Group – 14: Allotropes of carbon, the tendency for catenation; Structure; properties of silicates, and zeolites.
Group – 15: Properties and uses of nitrogen and phosphorus; Allotrophic forms of phosphorus; Preparation, properties, structure and uses of ammonia, nitric acid, phosphine and phosphorus halides, (PCl3, PCl5); Structures of oxides and oxoacids of phosphorus.
Group – 16: Preparation, properties, structures and uses of ozone; Allotropic forms of sulphur; Preparation, properties, structures and uses of sulphuric acid (including its industrial preparation); Structures of oxoacids of sulphur.
Group – 17: Preparation, properties and uses of hydrochloric acid; Trends in the acidic nature of hydrogen halides; Structures of Interhalogen compounds and oxides and oxoacids of halogens.
Group –18: Occurrence and uses of noble gases; Structures of fluorides and oxides of xenon.


UNIT 16: d – and f – BLOCK ELEMENTS

Transition Elements

General introduction, electronic configuration, occurrence and characteristics, general trends in properties of the first row transition elements – physical properties, ionization enthalpy, oxidation states, atomic radii, colour, catalytic behaviour, magnetic properties, complex formation, interstitial compounds, alloy formation; Preparation, properties and uses of K2 Cr2 O7 and KMnO4 .
Inner Transition Elements
Lanthanoids – Electronic configuration, oxidation states and lanthanoid contraction.
Actinoids – Electronic configuration and oxidation states.

UNIT 17: CO-ORDINATION COMPOUNDS

Introduction to co-ordination compounds, Werner’s theory; ligands, coordination number, denticity, chelation; IUPAC nomenclature of mononuclear co-ordination compounds, isomerism; Bonding-Valence bond approach and basic ideas of Crystal field theory, colour and magnetic properties; Importance of coordination compounds (in qualitative analysis, extraction of metals and in biological systems).

UNIT 18: ENVIRONMENTAL CHEMISTRY

Environmental pollution – Atmospheric, water and soil.
Atmospheric pollution – Tropospheric and Stratospheric
Tropospheric pollutants – Gaseous pollutants: Oxides of carbon, nitrogen and sulphur, hydrocarbons; their sources, harmful effects and prevention; Greenhouse effect and Global warming; Acid rain;
Particulate pollutants: Smoke, dust, smog, fumes, mist; their sources, harmful effects and prevention.
Stratospheric pollution- Formation and breakdown of ozone, depletion of ozone layer – its mechanism and effects.
Water Pollution – Major pollutants such as pathogens, organic wastes and chemical pollutants; their harmful effects and prevention.
Soil pollution – Major pollutants such as Pesticides (insecticides, herbicides and fungicides), their harmful effects and prevention.
Strategies to control environmental pollution.

SECTION-C

ORGANIC CHEMISTRY


UNIT 19: PURIFICATION AND CHARACTERISATION OF ORGANIC COMPOUNDS

Purification – Crystallization, sublimation, distillation, differential extraction and chromatography – principles and their applications

Qualitative analysis – Detection of nitrogen, sulphur, phosphorus and halogens

Quantitative analysis (basic principles only) – Estimation of carbon, hydrogen, nitrogen, halogens, sulphur, phosphorus

Calculations of empirical formulae and molecular formulae; Numerical problems in organic quantitative analysis

UNIT 20: SOME BASIC PRINCIPLES OF ORGANIC CHEMISTRY

Tetravalency of carbon; Shapes of simple molecules – hybridisation (s and p); Classification of organic compounds based on functional groups: – C = C –, – C h C – and those containing halogens, oxygen, nitrogen and sulphur; Homologous series; Isomerism – structural and stereoisomerism.
Nomenclature (Trivial and IUPAC)

Covalent bond fission – Homolytic and heterolytic: free radicals, carbocations and carbanions; stability of carbocations and free radicals, electrophiles and nucleophiles.

Electronic displacement in a covalent bond – Inductive effect, electromeric effect, resonance and hyperconjugation

UNIT 21: HYDROCARBONS

Classification, isomerism, IUPAC nomenclature, general methods of preparation, properties and reactions.

AlkanesConformations: Sawhorse and Newman projections (of ethane); Mechanism of halogenation of alkanes.

Alkenes Geometrical isomerism; Mechanism of electrophilic addition:
Addition of hydrogen, halogens, water, hydrogen halides (Markownikoff’s and peroxide effect); Ozonolysis and polymerisation.

AlkynesAcidic character; Addition of hydrogen, halogens, water and hydrogen halides; Polymerization.

Aromatic hydrocarbons – Nomenclature, benzene – structure and aromaticity; Mechanism of electrophilic substitution: halogenation, nitration, Friedel – Craft’s alkylation and acylation, directive influence of functional group in mono-substituted benzene.

UNIT 22: ORGANIC COMPOUNDS CONTAINING HALOGENS

General methods of preparation, properties and reactions; Nature of C-X bond; Mechanisms of substitution reactions. Uses; Environmental effects of chloroform - iodoform.


UNIT 23: ORGANIC COMPOUNDS CONTAINING OXYGEN

General methods of preparation, properties, reactions and uses

ALCOHOLS, PHENOLS AND ETHERS

Alcohols: Identification of primary, secondary and tertiary alcohols; mechanism of dehydration.

Phenols: Acidic nature, electrophilic substitution reactions: halogenation, nitration and sulphonation, Reimer – Tiemann reaction.

Ethers: Structure.

Aldehyde and Ketones: Nature of carbonyl group;Nucleophilic addition to >C=O group, relative reactivities of aldehydes and ketones; Important reactions such as – Nucleophilic addition reactions (addition of HCN, NH3 and its derivatives), Grignard reagent; oxidation; reduction (Wolff Kishner and Clemmensen); acidity of α – hydrogen, aldol condensation, Cannizzaro reaction, Haloform reaction; Chemical tests to distinguish between aldehydes and Ketones.

Carboxylic acids: Acidic strength and factors affecting it.

UNIT 24: ORGANIC COMPOUNDS CONTAINING NITROGEN

General methods of preparation, properties, reactions and uses

Amines: Nomenclature, classification, structure, basic character and identification of primary, secondary and tertiary amines and their basic character.

Diazonium Salts: Importance in synthetic organic chemistry.

UNIT 25: POLYMERS

General introduction and classification of polymers, general methods of polymerisation - addition and condensation, copolymerization; Natural and synthetic rubber and vulcanisation; some important polymers with emphasis on their monomers and uses – polyethene, nylon, polyester and bakelite

UNIT 26: BIOMOLECULES

General introduction and importance of biomolecules

CARBOHYDRATES – Classification: aldoses and ketoses; monosaccharides (glucose and fructose) and constituent monosaccharides of oligosaccharides (sucrose, lactose and maltose)
PROTEINS – Elementary Idea of  – amino acids, peptide bond, polypeptides; Proteins: primary, secondary, tertiary and quaternary structure (qualitative idea only), denaturation of proteins, enzymes.
VITAMINS – Classification and functions.
NUCLEIC ACIDS – Chemical constitution of DNA and RNA. Biological functions of nucleic acids.

UNIT 27: CHEMISTRY IN EVERYDAY LIFE

Chemicals in medicines – Analgesics, tranquillisers, antiseptics, disinfectants, antimicrobials, antifertility drugs, antibiotics, antacids, antihistamines – their meaning and common examples
Chemicals in food – Preservatives, artificial sweetening agents – common examples
Cleansing agents – Soaps and detergents, cleansing action


UNIT 28: PRINCIPLES RELATED TO PRACTICAL CHEMISTRY

Detection of extra elements (N, S, halogens) inorganic compounds;

Detection of the following functional groups: hydroxyl (alcoholic and phenolic), carbonyl (aldehyde and ketone), carboxyl and amino groups in organic compounds.

The chemistry involved in the preparation of the following:
Inorganic compounds: Mohr’s salt, potash alum.
Organic compounds: Acetanilide, pnitroacetanilide, aniline yellow, iodoform.

The chemistry involved in the titrimetric exercises – Acids bases and the use of indicators, oxalic-acid vs KMnO4, Mohr’s salt vs KMnO4.

Chemical principles involved in the qualitative salt analysis:

Cations – Pb2+, Cu2+, AI3+, Fe3+, Zn2+, Ni2+, Ca2+, Ba2+, Mg2+, NH4+.

Anions- CO3 2-, S2-, SO4 2-, NO2-, NO3-, CI -, Br, I. (Insoluble salts excluded).


Chemical principles involved in the following experiments:

Enthalpy of solution of CuSO4
Enthalpy of neutralisation of strong acid and strong base.
Preparation of lyophilic and lyophobic sols.
Kinetic study of the reaction of iodide ion with hydrogen peroxide at room temperature.


Updated 15 Jan 2020, 12 January 2020
9 Jan 2020




Sunday, January 12, 2020

JEE Main 2020 - ORGANIC CHEMISTRY Syllabus and Revision Points - Index

ORGANIC CHEMISTRY


UNIT 19: PURIFICATION AND CHARACTERISATION OF ORGANIC COMPOUNDS

Purification – Crystallization, sublimation, distillation, differential extraction and chromatography – principles and their applications

Qualitative analysis – Detection of nitrogen, sulphur, phosphorus and halogens

Quantitative analysis (basic principles only) – Estimation of carbon, hydrogen, nitrogen, halogens, sulphur, phosphorus

Calculations of empirical formulae and molecular formulae; Numerical problems in organic quantitative analysis

UNIT 20: SOME BASIC PRINCIPLES OF ORGANIC CHEMISTRY

Tetravalency of carbon; Shapes of simple molecules – hybridisation (s and p); Classification of organic compounds based on functional groups: – C = C –, – C h C – and those containing halogens, oxygen, nitrogen and sulphur; Homologous seriesIsomerism – structural and stereoisomerism.
Nomenclature (Trivial and IUPAC)

Covalent bond fission – Homolytic and heterolytic: free radicals, carbocations and carbanions; stability of carbocations and free radicals, electrophiles and nucleophiles.

Electronic displacement in a covalent bond – Inductive effect, electromeric effect, resonance and hyperconjugation

UNIT 21: HYDROCARBONS

Classification, isomerism, IUPAC nomenclature, general methods of preparation, properties and reactions.

Alkanes – Conformations: Sawhorse and Newman projections (of ethane); Mechanism of halogenation of alkanes.

Alkenes – Geometrical isomerismMechanism of electrophilic addition:
Addition of hydrogenhalogenswaterhydrogen halides (Markownikoff’s and peroxide effect)Ozonolysis and polymerisation.

Alkynes – Acidic character; Addition of hydrogen, halogens, water and hydrogen halides; Polymerization.

Aromatic hydrocarbons – Nomenclature, benzene – structure and aromaticity; Mechanism of electrophilic substitution: halogenationnitration, Friedel – Craft’s alkylation and acylation, directive influence of functional group in mono-substituted benzene.

UNIT 22: ORGANIC COMPOUNDS CONTAINING HALOGENS

General methods of preparationproperties and reactions; Nature of C-X bond; Mechanisms of substitution reactions. Uses; Environmental effects of chloroform - iodoform.


UNIT 23: ORGANIC COMPOUNDS CONTAINING OXYGEN

General methods of preparation, properties, reactions and uses

ALCOHOLS, PHENOLS AND ETHERS

Alcohols: Identification of primary, secondary and tertiary alcoholsmechanism of dehydration.

Phenols: Acidic nature, electrophilic substitution reactions: halogenation, nitration and sulphonationReimer – Tiemann reaction.

Ethers: Structure.

Aldehyde and Ketones: Nature of carbonyl group;Nucleophilic addition to >C=O group, relative reactivities of aldehydes and ketones; Important reactions such as – Nucleophilic addition reactions (addition of HCN, NH3 and its derivatives), Grignard reagent; oxidationreduction (Wolff Kishner and Clemmensen); acidity of α – hydrogen, aldol condensationCannizzaro reactionHaloform reaction; Chemical tests to distinguish between aldehydes and Ketones.

Carboxylic acids: Acidic strength and factors affecting it.

UNIT 24: ORGANIC COMPOUNDS CONTAINING NITROGEN

General methods of preparation, properties, reactions and uses

Amines: Nomenclatureclassification, structure, basic character and identification of primary, secondary and tertiary amines and their basic character.

Diazonium Salts: Importance in synthetic organic chemistry.

UNIT 25: POLYMERS

General introduction and classification of polymers, general methods of polymerisation - addition and condensation, copolymerization; Natural and synthetic rubber and vulcanisation; some important polymers with emphasis on their monomers and uses – polyethene, nylon, polyester and bakelite

UNIT 26: BIOMOLECULES

General introduction and importance of biomolecules

CARBOHYDRATES – Classification: aldoses and ketoses; monosaccharides (glucose and fructose) and constituent monosaccharides of oligosaccharides (sucrose, lactose and maltose)
PROTEINS – Elementary Idea of  – amino acids, peptide bond, polypeptides; Proteins: primary, secondary, tertiary and quaternary structure (qualitative idea only), denaturation of proteins, enzymes.
VITAMINS – Classification and functions.
NUCLEIC ACIDS – Chemical constitution of DNA and RNA. Biological functions of nucleic acids.

Saturday, January 11, 2020

Group 17 Halogens



Elements

Flourine (z = 9, 2p5)
Chlorine (z = 17, 3p5)
Bromine (z = 35, 4p5)
Iodine (z = 53, 5p5)
At (z = 85, 6p5)